People in industrialized nations spend more than 90% of their time indoors, and many industry-related occupations require personnel to work in conditions having airborne pollutants. The lung is the most common site of injury by airborne pollutants. Acute effects from airborne pollutants may also include non-respiratory signs and symptoms, which may depend upon toxicological characteristics of the substances involved.
To improve air quality, facilities use ventilation systems, which vary as to design, use, specifications, and maintenance. Most ventilation systems restrict the movement of air in and between various departments, and the systems may have specific ventilation and filtration capabilities to dilute and remove contamination, airborne microorganisms, viruses, hazardous chemicals, radioactive substances, and the like.
In addition to ventilation systems, some work environments can have hazards, and personnel need uncontaminated breathing air supplied to them while working in the hazardous environments. For example, various chemicals used in industrial processes are known to be hazardous to people in and around a work environment if the chemicals are not handled or ventilated properly. Vaporous chemicals, such as acetic acid, benzene, formaldehyde, nitrous oxide, and xylene, carry health warnings and can often affect a person's immune system if the person is exposed to the chemical.
In addition, situations arise in which volatile, toxic, and particulate laden gasses may be generated or leak into an interior room of a building or other confined space—potentially exposing personnel to hazards. Personnel in work environments may also be exposed to the presence of gasses, such as vapors from hydrocarbon based products as well as natural or liquefied petroleum gasses within an enclosure or confined space, such as an interior room of a building. In some cases, hazardous materials, such as volatile organic compounds, cannot be vented from an interior space to the atmosphere. Some examples of these volatile organic compounds include automobile and aircraft paints, resurfacing materials, porcelain paints, reducers, glues, cleaning agents, grain dust, and hydrocarbon fumes. These materials must be carefully evacuated from the interior space to avoid adverse effects, including unwanted combustion of such materials.
Accordingly, there has always been a need to produce and filter breathing air for personnel working in a variety conditions and potentially exposed to hazards. The subject matter of the present disclosure is directed to addressing this need.